34271-54-0

Usage

InChI:InChI=1/C7H14N2O3/c1-2-9-6(10)4-3-5(8)7(11)12/h5H,2-4,8H2,1H3,(H,9,10)(H,11,12)

Upstream product

• 95082-77-2 Z-L-theanine 
• 73270-47-0 L-glutamic acid-5-ethyl ester; hydrochloride 
• 75-04-7 ethylamine 
• 1499-55-4 L-glutamic acid 5-methyl ester 
• 557-66-4 ethanamine hydrochloride 
• 142-47-2 monosodium glutamate 
• 56-85-9 L-glutamine 
• 70-18-8 GLUTATHIONE 
• 865758-94-7 (S)-2-(1,3-Dioxo-1,3-dihydro-isoindol-2-yl)-4-ethylcarbamoyl-butyric acid 
• 142-47-2 monosodium L-glutamate 
• 1676-73-9 L-glutamic acid γ-benzyl ester 
• 116027-39-5 N-trityl-L-glutamic acid-5-benzyl ester 
• 56-86-0 L-glutamic acid 
• 593-51-1 methylamine hydrochloride 

Downstream Products

• 910541-97-8 L-theanyl-L-theanine 
• 56-86-0 L-glutamic acid 
• 75-04-7 ethylamine 
• 1000788-95-3 methyl ester theanine 

Relevant academic research and scientific papers

Varietal Differences in the Total and Enantiomeric Composition of Theanine in Tea

Theanine is the main amino acid component in tea. It usually constitutes between 1 and 2% of the dry weight of the tea leaves. It is as prevalent in tea as all other free amino acids combined. Both enantiomers of theanine were found to have a similar sweet taste, with little or no aftertaste. It was found that black and half-green teas (except for Formosa Oolong) contained as much, or more, theanine as green teas. No correlation was found between the absolute concentration of theanine in tea and its enantiomeric composition. An inverse correlation was found between certain grades of tea (e.g., pekoe, Flowery Orange Pekoe, etc.) and the percent of D-theanine present. This could provide the basis for a reproducible, scientific method to grade and/or evaluate teas. Theanine slowly racemizes in aqueous solution. It also undergoes hydrolysis, particularly at basic pH values. By monitoring these processes, information may be gleaned on the production, storage, handling, and shipping of tea and tea products.

Preparation method of L-theanine

The invention relates to the technical field of organic chemical synthesis, in particular to a preparation method of L-theanine. The preparation method of the L-theanine comprises the following steps:(a) reacting L-glutamic acid with a copper salt in a solvent to obtain a chelate A; (b) carrying out an esterification reaction on the chelate A and methanol to obtain a compound B; and (c) after a reaction of the compound B with an aqueous ethylamine solution is finished, adding a decoppering reagent, carrying out stirring for a reaction, and removing a solvent to obtain a crude L-theanine product. According to the preparation method of the L-theanine, the L-glutamic acid is used as an initial raw material and is easy to obtain; in addition, residues in amino acid are protected by adopting acopper chelate manner, so the reaction process is green and environment-friendly. In the step (c), the safer aqueous ethylamine solution is used for the reaction, so the safety of the reaction is improved, requirements on equipment are reduced, production cost is greatly saved, and industrial production is easier.

Characterization of l -Theanine Excitatory Actions on Hippocampal Neurons: Toward the Generation of Novel N-Methyl- d -aspartate Receptor Modulators Based on Its Backbone

l-Theanine (or l-γ-N-ethyl-glutamine) is the major amino acid found in Camellia sinensis. It has received much attention because of its pleiotropic physiological and pharmacological activities leading to health benefits in humans, especially. We describe here a new, easy, efficient, and environmentally friendly chemical synthesis of l-theanine and l-γ-N-propyl-Gln and their corresponding d-isomers. l-Theanine, and its derivatives obtained so far, exhibited partial coagonistic action at N-methyl-d-aspartate (NMDA) receptors, with no detectable agonist effect at other glutamate receptors, on cultured hippocampal neurons. This activity was retained on NMDA receptors expressed in Xenopus oocytes. In addition, both GluN2A and GluN2B containing NMDA receptors were equally modulated by l-theanine. The stereochemical change from l-theanine to d-theanine along with the substitution of the ethyl for a propyl moiety in the γ-N position of l- and d-theanine significantly enhanced the biological efficacy, as measured on cultured hippocampal neurons. l-Theanine structure thus represents an interesting backbone to develop novel NMDA receptor modulators.

Studies on the Biochemical Formation Pathway of the Amino Acid l -Theanine in Tea (Camellia sinensis) and Other Plants

Tea (Camellia sinensis) is the most widely consumed beverage aside from water. The flavor of tea is conferred by certain metabolites, especially l-theanine, in C. sinensis. To determine why more l-theanine accumulates in C. sinensis than in other plants, we compare l-theanine contents between C. sinensis and other plant species (Camellia nitidissima, Camellia japonica, Zea mays, Arabidopsis thaliana, and Solanum lycopersicum) and use a stable isotope labeling approach to elucidate its biosynthetic route. We quantify relevant intermediates and metabolites by mass spectrometry. l-Glutamic acid, a precursor of l-theanine, is present in most plants, while ethylamine, another precursor of l-theanine, specifically accumulates in Camellia species, especially C. sinensis. Most plants contain the enzyme/gene catalyzing the conversion of ethylamine and l-glutamic acid to l-theanine. After supplementation with [2H5]ethylamine, all the plants produce [2H5]l-theanine, which suggests that ethylamine availability is the reason for the difference in l-theanine accumulation between C. sinensis and other plants.

Application of recombinant Bacillus subtilis γ-glutamyltranspeptidase to the production of l-theanine

l-Theanine, which has seen increasing use in the functional food industry, can be prepared via enzymatic synthesis using γ-glutamyltranspeptidase (GGT; EC 2.3.2.2). In this study, the GGT from Bacillus subtilis 168 was cloned and expressed as a secreted protein using Escherichia coli BL21(DE3). The enzymatic properties of the GGT and the optimal conditions for the enzymatic synthesis of l-theanine were investigated in detail. The activity of the enzyme was optimal at pH 10; the optimal temperature was 50 °C. Desirable pH stability was observed between pH 5 and pH 12, and adequate thermostability was seen at 50 °C. In 5 h at 37 °C, the enzyme converted 200 mM l-glutamine and 2.2 M ethylamine to l-theanine with a final yield of 78%. Yields of l-theanine decreased to 58% when using 500 mM Gln and 45% when using 1 M Gln. The yield of l-theanine obtained at high substrate concentration provides the basis for the industrial-scale production of l-theanine.

Synthesis of amino acid using a flow-type microreactor containing enzyme-mesoporous silica microsphere composites

A flow-type microreactor containing composite materials of a theanine synthetase (glutaminase) and mesoporous silica with 23.6 nm pore diameter (SBA-15 microsphere) was developed for the continuous synthesis of l-theanine, a unique amino acid. Enzyme-immobilisation ability and enzymatic activity in the SBA-15 microsphere with large mesopores were higher than those of SBA-15 with a 5.4 nm pore diameter. Moreover, the glutaminase-SBA-15 microsphere composites displayed higher selectivity in theanine production than the free enzyme did in a batch experiment. A direct visualization of composites of fluorescently labelled glutaminase and SBA-15 microsphere immobilised in the flow channel of the microreactor by a combination of differential interference contrast and fluorescence microscopy revealed that the enzymes were uniformly dispersed throughout the mesoporous silica particles, because of the successful encapsulation of the enzyme. The enzyme-encapsulated microreactor exhibited a high conversion of l-glutamine to l-theanine with local control of the reaction temperature. In addition to this advantage of the microreaction system, the microreactor enabled the on-off regulation of enzymatic activity during continuous theanine synthesis by controlling the reaction temperature or the pH of the substrate solution.

Molecular cloning and characterization of γ-Glutamyltranspeptidase from pseudomonas nitroreducens IFO12694

y-Glutamyltranspeptidase from Pseudomonas nitroreducens IFO12694 (PnGGT) exhibited higher hydro-lytic activity than transfer activity, as compared with other y-glutamyltranspeptidases (GGTs). PnGGT showed little activity towards most of L-amino acids and towards glycyl-glycine, which is often used as a standard y-glutamyl accepter in GGT transfer reactions. The preferred substrates for PnGGT as a y-glutamyl accepter were amines such as methylamine, ethylamine, and isopropylamine.

Enzymatic synthesis of theanine from glutamic acid γ-methyl ester and ethylamine by immobilized Escherichia coli cells with γ- glutamyltranspeptidase activity

Theanine (γ-glutamylethylamide) is the main amino acid component in green tea. The demand for theanine in the food and pharmaceutical industries continues to increase because of its special flavour and multiple physiological effects. In this research, an improved method for enzymatic theanine synthesis is reported. An economical substrate, glutamic acid γ-methyl ester, was used in the synthesis catalyzed by immobilized Escherichia coli cells with γ-glutamyltranspeptidase (GGT) activity. The results show that GGT activity with glutamic acid γ-methyl ester as substrate was about 1.2-folds higher than that with glutamine as substrate. Reaction conditions were optimized by using 300 mmol/l glutamic acid γ-methyl ester, 3,000 mmol/l ethylamine, and 0.1 g/ml of immobilized GGT cells at pH 10 and 50°C. Under these conditions, the immobilized cells were continuously used ten times, yielding an average glutamic acid γ-methyl ester to theanine conversion rate of 69.3%. Bead activity did not change significantly the first six times they were used, and the average conversion rate during the first six instances was 87.2%. The immobilized cells exhibited favourable operational stability.

A novel catalytic ability of γ-glutamylcysteine synthetase of Escherichia coli and its application in theanine production

γ-Glutamylcysteine synthetase (γGCS, EC 6.3.2.2) catalyzes the formation of γ-glutamylcysteine from L-glutamic acid (Glu) and L-cysteine (Cys) in an ATP-dependent manner. While γGCS can use various amino acids as substrate, little is known about whether it can use non-amino acid compounds in place of Cys. We determined that γGCS from Escherichia coli has the ability to combine Glu and amines to form γ-glutamylamides. The reaction rate depended on the length of the methylene chain of the amines in the following order: n-propylamine > butylamine > ethylamine methylamine. The optimal pH for the reaction was narrower and more alkaline than for the reaction with an amino acid. The newly found catalytic ability of γGCS was used in the production of theanine (γ-glutamylethylamine). The resting cells of E. coli expressing γGCS, in which ATP was regenerated through glycolysis, synthesized 12.1 mm theanine (18 h) from 429 mm ethylamine.

Process for purifying theanine

The present invention provides a process for purifying theanine from an aqueous solution having a dominant cation and comprising impurities. The process comprises the steps of: introducing the aqueous solution into a column in an amount of from 2 to 20% of the column volume, wherein the column is packed with a cation exchange resin of the same cation type as the dominant cation; then introducing an aqueous mobile phase having a pH of from 2.5 to 8.5 into the column thereby to elute a zone enriched in the impurities followed by a zone enriched in theanine; and then recovering at least one fraction of the zone enriched in theanine.